Values available are the sides p, q, r, s and the crank angle θ. You can work out all coordinates easily once you know the rocker angle γ. This sequence of calculations can derive it:
1. Calculate d using the Cosine Rule in the lower triangle, since you know the opposite angle and the other two sides.
2. Calculate α using the Sine Rule.
3. Calculate β by applying the Cosine Rule to the upper triangle, re-arranging the formula to give the angle.
4. Obtain γ from the relation α + β + γ = 180°

I used the cosine and sine rule and pythagorus theorem but the final equations i get i get variables that are unknown.